Solar Panel Degradation: Separating the Facts From Fiction


Solar panels are susceptible to a performance-affecting phenomenon. Known as degradation, it will affect their power output. Solar panels are designed to convert sunlight into electricity. Over time, however, solar panels will become less efficient at converting sunlight into electricity.

What Is Degradation?

Degradation is the gradual loss of a solar panel’s power output over time. New solar panels typically have the greatest output. They can convert more sunlight into electricity than their older counterparts. The term “degradation” refers to a solar panel’s loss of power output over time.

Are All Types of Solar Panels Suscecptiple to Degradation?

While some of them experience a greater loss of power output over time, all types of solar panels are susceptible to degradation. There are three primary types of solar panels: thin film, monocrystalline and polycrystalline.

Thin-film solar panels are the most susceptible to degradation. They lose their power output more quickly than monocrystalline and polycrystalline solar panels. Polycrystalline solar panels degrade more slowly than thin-film solar panels but faster than monocrystalline solar panels.

Should You Be Concerned About Degradation?

If you choose monocrystalline or polycrystalline solar panels, degradation shouldn’t be an issue. A study conducted by the National Renewable Energy Laboratory revealed that solar panels have an average deterioration rate of 0.5% per year. Most solar panels — with the exception of thin-film solar panels — will only lose about 0.5% of their power output per year.

Based on the aforementioned data, solar panels will only lose about 5% of their power output per decade. If you own a solar panel installation for 20 years, your solar panels will only be 10% less efficient by the end of the 20-year mark.

What Causes Degradation?

You might be wondering what causes solar panels to degrade. There’s no single underlying cause. Rather, degradation is the result of many different factors, one of which is heat.

Studies have shown that solar panels installed in warm regions have a faster rate of degradation than those installed in regions with a mild or moderate climate. Ultraviolet (UV) is a contributing factor to degradation. Solar panels are designed to be directly exposed to UV light, which is essentially how they generate electricity. But long-term exposure to UV light can take a toll on solar panels.

Ice can cause solar panels to degrade. When the temperature drops below freezing, condensation on the surface of a solar panel may freeze. As ice constantly forms over the course of many years, it can reduce the power output of the solar panel.

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